Translation

Question 1

General procedures

Answer 1

Initiation

Elongation

Termination

Question 2

Describe initiation @euk

Answer 2

40S rib subunit binds to initiator tRNA carrying methionine;

Initiation complex binds to 5’ 7met cap;

AUG;

60s binds to initiation complex;

Functional ribosome at start codon

Question 3

Describe elongation

Answer 3

Initiator tRNA binds to P site of large rib;

A site vacant for next aminoacyl tRNA complex;

Second aminoacyl-tRNA complex contains anticodon complementary to next codon on mRNA at A site;

Peptidyl transferase at P, catalyses the formation of peptide bond bt met and second aa;

Translocation of ribosome;

Ribosome moves along mRNA in 5’->3’;

Question 4

Describe termination

Answer 4

Ribosome reaches termination codon;

Release factor binds;

Water molecules binds to A-site;

Peptidyl transferase hydrolysis the bond bt polypeptide chain and tRNA at P site;

Release mRNA and polypeptide chains;

Ribosome disassembles